How Python really works: CPython internals

Go under the hood of the interpreter that runs most Python. Start with the object and data model, where every value is a heap object and behavior lives in dunder methods. See how source becomes bytecode and runs on a stack machine with an adaptive interpreter. Learn how reference counting and the cyclic collector reclaim memory. Finish with the GIL and the free-threading build that makes it optional. Come out able to reason about performance, memory, and concurrency from mechanism, not folklore.